Cobaloxime 1,3-Dienyl Complexes
Organometallics, Vol. 25, No. 4, 2006 979
H-6, 7), 2.14 (s, 6H), 2.09 (s, 6H), 1.91-2.03 (m, 1H, H-10),
1.06 (d, J ) 5.7 Hz, 3H, H-12); 13C NMR (75.5 MHz, CDCl3) δ
208.8 (C-11), 154.2 (C), 150.2 (C), 149.8 (C), 149.0 (CH), 138.7
(C-8), 129.5 (C-2), 127.9 (C-5), 124.4 (C-4), 121.5 (C-3), 107.5
(CH), 64.6 (C-6), 55.6 (C-1), 39.0 (CH3), 37.1 (C-10), 36.7
(C-7), 19.4 (C-12), 12.2 (CH3), 12.0 (CH3); Anal. Calcd for
C27H37CoN6O5: C, 55.46; H, 6.38. Found: C, 55.76; H, 6.42.
2.97-3.10 (m, 2H, H-6,7), 2.18 (s, 6H), 2.12 (s, 6H), 1.94-1.99
(m, 1H, H-10), 1.19 (d, J ) 6.2 Hz, 3H, H-12); 13C NMR (75.5
MHz, CDCl3) δ 206.4 (C-11), 166.9 (C-2), 158.7 (C-13), 150.8
(C), 150.3 (C), 150.2 (CH), 141.0 (C), 137.9 (C-8), 137.5 (CH),
135.4 (C-4), 129.1 (CH), 128.1 (CH), 126.6 (CH), 125.2 (CH),
125.1 (C-2), 119.5 (C-5), 63.9 (C-6), 52.1 (C-1), 37.3 (C-10), 36.3
(C-7), 19.4 (C-12), 12.3 (CH3), 12.1 (CH3); HRMS calcd for C34H40-
CoN5O8 (M)+ 705.2209, found 705.2202. Cycloadduct 12a: amor-
phous yellow-brown solid (0.028 g, 0.04 mmol, 53%); mp (neat)
( 210 °C dec; Rf 0.328 (diethyl ether/pentane, 3:2); 1H NMR (500
MHz, TMS) δ 8.47 (d, J ) 5.2 Hz, 2H), 7.59 (at, J ) 7.6 Hz, 1H),
7.03-7.32 (m, 7H), 5.79 (s, 1H, H-2), 5.52 (s, 1H, H-5), 5.15 (d,
J ) 5.5 Hz, 1H, H-10), 3.54 (s, 3H, H-14), 3.48 (s, 3H, H-15),
3.03 (dd, J ) 12.3, 5.5 Hz, 1H, H-7), 2.51 (p, J ) 6.3 Hz, 1H,
H-11), 2.27-2.36 (m, 1H, H-8), 1.85-1.95 (m, 1H, H-8), 1.72 (s,
6H), 1. 70 (s, 6H), 0.72 (d, J ) 6.8 Hz, 3H, H-12); 13C NMR (75.5
MHz, CDCl3) δ 200.8 (C-6), 173.8 (C-13), 163.3 (C-4), 150.0 (CH),
149.7 (C), 140.4 (C-2), 139.6 (C), 137.7 (C-3), 137.5 (CH), 128.0
(CH), 127.9 (CH), 127.5 (C-10), 127.3 (CH), 125.1 (CH), 106.9
(C-5), 55.4 (C-15), 51.8 (C-14), 51.2 (C-7), 50.5 (C-1), 43.0 (C-
11), 32.9 (C-8), 17.7 (C-12), 11.8 (CH3); HRMS calcd for C34H41-
CoN5O8 (M + H)+ 706.2287, found 706.2283.
Synthesis of (10â-Methyl-(1â-methyl,6Hâ)-bicyclo[4.4.1]-
undeca-2,4,8-trien-11-one-8-yl)(4′-N,N-dimethylamino)pyridinebis-
(dimethylglyoximato)cobalt (9a). Diene 1 (0.100 g, 0.209 mmol)
and tropone (8, R1 ) Me) (0.050 g, 0.418 mmol) were heated for
72 h according to the general procedure. Purification of the
compound by column chromatography yielded cycloadduct 9a
(0.055 g, 0.092 mmol, 44%) as a yellow amorphous material: mp
1
(neat) 154 °C dec; Rf 0.189 (diethyl ether/hexane, 3:2); H NMR
(300 MHz, CDCl3) δ 8.09 (d, J ) 7.2 Hz, 2H), 6.39 (d, J ) 7.2
Hz, 2H), 5.77 (dd, J ) 11.7, 7.2 Hz, 1H, H-4), 5.71 (dd, J ) 11.7,
7.2 Hz, 1H, H-3), 5.25-5.39 (m, 3H, H-2, 5, 9), 3.30-3.42 (m,
1H, H-6), 2.91-3.09 (m, 2H, H-7, 10), 2.96 (s, 6H), 2.14 (s, 6H),
2.08 (s, 6H), 1.91-2.01 (m, 1H, H-7), 1.01 (s, 3H, H-13), 0.96 (d,
J ) 6.8 Hz, 3H, H-12); 13C NMR (75.5 MHz, CDCl3) δ 209.2
(C-11), 154.2 (C), 150.2 (C), 149.8 (C), 149.1 (CH), 138.5 (C-9),
135.1 (C-2), 130.8 (C-5), 123.7 (C-3), 120.7 (C-4), 107.5 (CH),
60.8 (C-1), 54.9 (C-6), 39.0 (CH), 37.1 (C-10), 37.0 (C-7), 18.5
(C-13), 15.3 (C-12), 12.1 (CH3), 11.9 (CH3); HRMS calcd for
C28H40CoN6O5 (M + H)+ 599.2392, found 599.2399.
Diels-Alder [4 + 2] Cycloaddition Reactions. Synthesis of
(1â,3-Dicarboethoxy-7Hâ,11â-methyl)-5-methoxy-bicyclo[5.4.0]-
undeca-2,5,9-trien-4-one-9-yl)(4′-N,N-dimethylamino)pyridinebis-
(dimethylglyoximato)cobalt (15a). Diene 1 (0.074 g, 0.155 mmol)
and tropone 14a (0.064 g, 0.228 mmol) were heated for 36 h
according to the general procedure mentioned above. The compound
was purified by flash chromatography to afford cycloadduct 15a
(0.078 g, 0.103 mmol, 67%) as a yellowish-brown powder. The
product was further purified by dual solvent recrystallization using
ethyl acetate to dissolve the compound and the cyclohexane for
slow diffusion: mp (neat) ( 135 °C; Rf 0.133 (ethyl acetate/hexane,
Synthesis of (10â-Methyl-(1â-phenyl,6Hâ)-bicyclo[4.4.1]-
undeca-2,4,8-trien-11-one-8-yl)(4′-N,N-dimethylamino)pyridinebis-
(dimethylglyoximato)cobalt (9b). Diene 1 (0.200 g, 0.418 mmol)
and tropone (8, R1 ) Ph) (0.138 g, 0.758 mmol) were heated for
72 h according to the general procedure. Initial chromatographic
separation of the crude product yielded excess tropone (8, R1 )
Ph) (0.084 g, 0.462 mmol, 61%) followed by the cycloadduct 9b
and unreacted diene 1 as a dark yellow mixture (0.119 g): Rf 0.64
(100% diethyl ether). Further purification of the cobaloxime mixture
by another column chromatography yielded the pure cycloadduct
9b (0.073 g, 0.111 mmol, 26%) as a yellow powder: mp (neat)
1
3:1); H NMR (500 MHz, CDCl3) δ 8.04 (d, J ) 7.1 Hz, 2H),
6.64 (bs, 1H, H-2), 6.38 (d, J ) 7.1 Hz, 2H), 5.87 (d, J ) 8.7 Hz,
1H, H-6), 5.32 (bd, J ) 5.5 Hz, 1H, H-10), 4.17-4.25 (m, 1H,
H-17), 4.09-4.17 (m, 1H, H-17), 3.94-4.06 (m, 2H, H-14), 3.56
(s, 3H, H-19), 2.95 (s, 6H), 2.85-2.92 (m, 1H, H-7), 2.47-2.60
(m, 2H, H-8, 11), 2.08 (s, 6H), 2.03 (s, 6H), 1.62-1.72 (dd, J )
18.5, 11.2 Hz, 1H, H-8), 1.27 (t, J ) 7.1 Hz, 3H, H-18), 1.11 (t, J
) 7.1 Hz, 3H, H-15), 0.76 (d, J ) 6.8 Hz, 3H, H-12); 13C NMR
(75.5 MHz, CDCl3) δ 184.7 (C-4), 171.8 (C-13), 165.8 (C-16),
154.2 (C), 150.9 (C-5), 149.7 (C-9), 149.1 (C-1), 148.9 (CH), 148.7
(C-2), 135.3 (C-3), 127.0 (C-10), 119.1 (C-6), 107.5 (CH), 61.2
(C-17), 60.9 (C-14), 55.4 (C-19), 53.3 (C), 42.4 (C-11), 39.0 (CH3),
37.0 (C-8), 33.9 (C-7), 18.0 (C-12), 14.06 & 14.00 (C-15, 18),
11.92, and 11.89 (dmg CH3’s); HRMS calcd for C34H47CoN6O10
(M + H)+ 759.2764, found 759.2762.
1
156-159 °C; Rf 0.16 (hexanes/diethyl ether, 4:1); H NMR (500
MHz, CDCl3) δ 8.13 (d, J ) 6.6 Hz, 2H), 7.29-7.36 (m, 2H, H-15),
7.18-7.24 (m, 3H, H-14, 16), 6.42 (d, J ) 6.6 Hz, 2H), 6.05 (d,
J ) 12.1 Hz, 1H, H-2), 5.90 (dd, J ) 12.1, 7.6 Hz, 1H, H-3), 5.81
(dd, J ) 11.3, 7.6 Hz, 1H, H-4), 5.68 (dd, J ) 11.3, 7.1 Hz, 1H,
H-5), 5.63 (d, J ) 7.6 Hz, 1H, H-9), 3.40 (p, J ) 7.1 Hz, 1H,
H-10), 3.13-3.25 (m, 1H, H-6), 2.90-3.06 (m, 1H, H-7), 2.98 (s,
6H), 2.13-2.20 (m, 1H, H-7), 2.11 (s, 6H), 2.02 (s, 6H), 0.81 (d,
J ) 7.1 Hz, 3H, H-12); 13C NMR (75.5 MHz, CDCl3) δ 207.9
(C-11), 154.2 (C), 150.2 (C), 149.9 (C), 149.0 (CH) 141.2 (C-13),
132.1 (C-2), 131.2 (C-5), 130.2 (C-15), 127.4 (C-14), 126.1 (C-
16), 122.3 (C-3), 121.3 (C-4), 107.5 (CH), 71.5 (C-1), 55.2 (C-6),
42.6 (C-10), 39.0 (CH3), 37.5 (C-7), 16.2 (C-12), 12.2 (CH3), 12.0
(CH3); HRMS calcd for C33H42CoN6O5 (M + H)+ 661.2548, found
661.2542.
Synthesis of (1â-Carbomethoxy,7Hâ,11â-methyl)-6-methoxy-
3-phenyl-bicyclo[5.4.0]undeca-2,5,9-trien-4-one-9-yl)(4′-N,N-
dimethylamino)pyridinebis(dimethylglyoximato)cobalt (15b).
Diene 1 (0.060 g, 0.125 mmol) and tropone 14b (0.050 g, 0.185
mmol) were heated for 22 h according to the general procedure
mentioned above. The compound was purified by flash chroma-
tography to yield cycloadduct 15b (0.035 g, 0.047 mmol, 38%) as
an amorphous brown powder: mp (neat) ( 206 °C dec; Rf 0.326
Synthesis of (7â-Methyl-(1Hâ,6Hâ)-5-carbomethoxy-2-meth-
oxy-3-phenyl-bicyclo[4.4.1]undeca-2,4,8-trien-11-one-9-yl)py-
ridinebis(dimethylglyoximato)cobalt (11a) and (1â-Carbo-
methoxy, 7Hâ,11â-methyl)-4-methoxy-3-phenylbicyclo[5.4.0]-
undeca-2,4,9-trien-6-one-9-yl)pyridinebis(dimethylglyoximato)-
cobalt (12a). Diene 4b (0.033 g, 0.078 mmol) and tropone 10a
(0.021 g, 0.078 mmol) were heated for 25 h according to the general
procedure mentioned above. The compound was purified by flash
chromatography, which afforded cycloadducts 11a and 12a (0.036
g, 0.051 mmol, 68%). Cycloadduct 11a: amorphous blackish-green
solid (0.008 g, 0.011 mmol, 15%); Rf 0.234 (diethyl ether/pentane,
1
(ethyl acetate); H NMR (500 MHz, CDCl3) δ 8.00 (d, J ) 7.0
Hz, 2H), 7.34-7.11 (m, 5H), 6.35 (d, J ) 7.0 Hz, 2H), 6.00 (s,
1H, H-2), 5.45 (s, 1H, H-5), 5.27 (d, J ) 5.5 Hz, 1H, H-10), 3.70
(s, 3H, H-15), 3.58 (s, 3H, H-14), 2.93 (s, 6H), 2.83 (dd, J ) 8.6,
5.2 Hz, 1H, H-7), 2.59 (dd, J ) 11.9, 5.5 Hz, 1H, H-8), 2.48-2.56
(m, 1H, H-11), 1.93-2.03 (m, 1H, H-8), 1.86 (s, 6H), 1.79 (s, 6H),
0.76 (d, J ) 7.0 Hz, 3H, H-12); 13C NMR (75.5 MHz, CDCl3) δ
189.1 (C-4), 179.0 (C-6), 173.5 (C-13), 154.1 (C), 149.3 (C), 149.1
(C), 148.8 (CH), 142.5 (C-3), 140.3 (C-2), 140.2 (C), 128.5 (CH),
127.8 (CH), 127.1 (CH), 126.9 (C-10), 107.4 (CH), 104.2 (C-5),
56.0 (C-15), 51.9 (C-14), 51.6 (C-1), 43.3 (C-11), 41.9 (C-7), 38.9
1
3:2); H NMR (500 MHz, CDCl3) δ 8.64 (d, J ) 5.1 Hz, 2H),
7.71 (at, J ) 7.6 Hz, 1H), 7.27-7.34 (m, 4H), 7.15-7.24 (m, 4H),
5.34 (ad, J ) 6.2 Hz, 1H, H-8), 3.79 (s, 3H, H-15), 3.57 (at, J )
9.0 Hz, 1H, H-1), 3.39 (s, 3H, H-14), 3.15-3.25 (m, 1H, H-10),